<template>
  <div
    ref="rightPanel"
    :class="{show:show}"
    class="rightPanel-container">
    <div class="rightPanel-background" />
    <div class="rightPanel">
      <div
        class="handle-button"
        :style="{'top':buttonTop+'px','background-color':theme}"
        @click="handleClick">
        <i :class="show?'el-icon-close':'el-icon-setting'" />
      </div>
      <div class="rightPanel-items">
        <slot />
      </div>
    </div>
  </div>
</template>

<script>
import { addClass, removeClass } from '@/utils'

export default {
  name: 'RightPanel',
  props: {
    clickNotClose: {
      default: false,
      type: Boolean
    },
    buttonTop: {
      default: 250,
      type: Number
    }
  },
  data() {
    return {
      show: false
    }
  },
  computed: {
    theme() {
      return this.$store.state.settings.theme
    }
  },
  watch: {
    show(value) {
      if (value && !this.clickNotClose) {
        this.addEventClick()
      }
      if (value) {
        addClass(document.body, 'showRightPanel')
      } else {
        removeClass(document.body, 'showRightPanel')
      }
    }
  },
  mounted() {
    this.insertToBody()
    this.top = this.buttonTop
    this.onmousemove = false
    this.handleMove()
  },
  beforeDestroy() {
    const elx = this.$refs.rightPanel
    elx.remove()
  },
  methods: {
    addEventClick() {
      window.addEventListener('click', this.closeSidebar)
    },
    closeSidebar(evt) {
      const parent = evt.target.closest('.rightPanel')
      if (!parent) {
        this.show = false
        window.removeEventListener('click', this.closeSidebar)
      }
    },
    insertToBody() {
      const elx = this.$refs.rightPanel
      const body = document.querySelector('body')
      body.insertBefore(elx, body.firstChild)
    },
    handleClick() {
      if (!this.onmousemove) {
        this.show = !this.show
      }
    },
    handleMove() {
      let startTime, endTime
      this.$nextTick(_ => {
        const button = document.querySelector('.handle-button')
        const buttonH = button.offsetHeight
        button.onmousedown = e => {
          this.onmousemove = true
          startTime = new Date().getTime()
          const startY = e.y
          // ie阻止默认事件
          if (button.setCapture) {
            button.setCapture()
          }
          document.onmousemove = e => {
            const endY = e.y
            button.style.cursor = 'move'
            let moveY = this.top + (endY - startY)
            if (moveY < 0) {
              moveY = 0
            } else if (moveY > window.innerHeight - buttonH) {
              moveY = window.innerHeight - buttonH
            }
            button.style.top = moveY + 'px'
            e.preventDefault()
          }
          document.onmouseup = e => {
            endTime = new Date().getTime()
            if (endTime - startTime < 300) {
              this.onmousemove = false
            }
            button.style.cursor = 'pointer'
            this.top = parseFloat(window.getComputedStyle(button, null).top)
            if (button.releaseCapture) {
              button.releaseCapture()
            }
            document.onmousemove = document.onmouseup = null
          }
        }
      })
    }
  }
}
</script>

<style>
.showRightPanel {
  overflow: hidden;
  position: relative;
  width: calc(100% - 15px);
}
</style>

<style lang="scss" scoped>
.rightPanel-background {
  position: fixed;
  top: 0;
  left: 0;
  opacity: 0;
  transition: opacity .3s cubic-bezier(.7, .3, .1, 1);
  background: rgba(0, 0, 0, .2);
  z-index: -1;
}

.rightPanel {
  width: 100%;
  max-width: 260px;
  height: 100vh;
  position: fixed;
  top: 0;
  right: 0;
  box-shadow: 0px 0px 15px 0px rgba(0, 0, 0, .05);
  transition: all .25s cubic-bezier(.7, .3, .1, 1);
  transform: translate(100%);
  background: #fff;
  z-index: 40000;
}

.show {
  transition: all .3s cubic-bezier(.7, .3, .1, 1);

  .rightPanel-background {
    z-index: 20000;
    opacity: 1;
    width: 100%;
    height: 100%;
  }

  .rightPanel {
    transform: translate(0);
  }
}

.handle-button {
  width: 48px;
  height: 48px;
  position: absolute;
  left: -48px;
  text-align: center;
  font-size: 24px;
  border-radius: 6px 0 0 6px !important;
  z-index: 0;
  pointer-events: auto;
  cursor: pointer;
  color: #fff;
  line-height: 48px;
  i {
    font-size: 24px;
    line-height: 48px;
  }
}
</style>
